摘要:

This paper reports the findings of studies on the biology of the California flatheaded borer (Melanophila californicaVan Dyke). Until comparatively recently this insect had been regarded as a relatively unimportant element of the western pine beetle problem. It has been shown that larval broods may spend a period of up to several years in an incipient stage in the living host tree. During this period the gallery of the incipient stage larva is healed over and the abnormal tissues thus developed interfere with normal conduction in the wood. Undetermined factors associated with the dying of the host tree initiate a fast-growing larval stage in which feeding is voracious and growth rapid.No attempt is made to set forth the role of the species in the complex known as the western pine beetle problem. It is, however, suggested that this insect, at least in northeastern California, may play a more important role in insect caused losses in commercial stands of ponderosa and Jeffrey pine than had previously been believed. The contributions to the knowledge of the biology of the species may assist in an eventual better understanding of insect–host relationships in this particular problem.

ISSN:1923-4287    

DOI:10.1139/cjr47d-007

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

The proventriculus of the rove-beetle,Staphylinus badipesLec., is described. It is similar in form to the proventriculi of beetles of the Staphylinidae and Silphidae, described by other authors, in that its sclerotized lining is arranged in eight longitudinal ridges alternating with eight rows of fine hairs.

ISSN:1923-4287    

DOI:10.1139/cjr47d-008

出版商:NRC Research Press    

年代:1947

数据来源: NRC

摘要:

Analyses of the contents of the caecal pouches and the small intestine have been made on chickens sacrificed four hours after dosing with sulphonamides. Sulphamerazine was found constantly in the caeca in small amounts even when the caeca were surgically detached from the rest of the intestinal tract, thus showing that the drug is excreted via the caeca to some extent. This property was found to be common also to sulphathiazole, sulphapyridine, and sulphanilamide. The importance of this finding lies in the fact that caecal coccidiosis of chicks is inhibited by sulphamerazine but not by the other three sulphonamides mentioned. It follows that the inhibitory effect is related to drug structure rather than to drug concentration.

ISSN:1923-4287    

DOI:10.1139/cjr47d-009

出版商:NRC Research Press    

年代:1947

数据来源: NRC